Thursday, May 24, 2012

Can We Finally Say PSA Tests Are a Waste of Time?

The latest findings reported by the U.S. Preventive Services Task Force which had culled thousands of medical reports and analyzed them, ought to show once and for all that the yearly PSA tests most older American males go through amount to a numbers game, a waste of time, and more often than not ... a treacherous ride of pain, unresolved medical conditions and expense ....through the American Medical -Industrial-PhRmA complex. Do men really want to take this trip?

Earlier, I showed the much vaunted "PSA velocity" which many American urologists rely on to determine the need for a biopsy is also not productive or reliable, viz,

In that blog I cited research originally appearing in The Journal of the National Cancer Institute, February 24, 2011 and authored by Dr. Andrew Vickers and Hans Lilja, who concluded that PSA velocity as a guideline would be unlikely to improve patient outcomes, adding, "we therefore recommend that organizations issuing policy statements related to PSA and prostate cancer detection remove references to PSA velocity."

Now, the U.S. Preventive Task Force, comprised of some of the finest specialists, physicians in the land, have similarly come down against regular PSA tests for healthy men. As one of the Panel chairs, Virginia A. Moyer has observed in her column in yesterday's Denver Post (p. 21A):

"Science finds that there is at best a small potential benefit from prostate cancer screening and there are substantial known harms. We need a better test and we need better options. We can do better."

Indeed. Now, to see how bad this PSA test is as a gauge let's look at some of the statistics dredged out (op. cit.) by the task force and put them into perspective:

- Of every 1,000 men screened via the PSA only ONE will avoid a prostate cancer death in the course of 10 years (the largest study ever conducted in the U.S. found no benefit at all, zero men avoiding prostate cancer death via PSA screening)

- Of the same 1,000 screened, 2-3 will suffer a serious complication of treatment including bowel blockage or rupture, blood clot, heart attack or a stroke leaving the guy a vegetable.

- As many as 40 of the same 1,000 screened will suffer erectile dysfunction for the rest of their lives which no device, medication or operation will fix

- Up to 40 will suffer from urinary incontinence and have to wear adult diapers for the rest of their days.

- And 30-40 of the 1,000 will suffer severe complications including incontinence, or urinary -other infections merely as a result of a prostate biopsy.

Even allowing for total overlap of the subsets for erectile dysfunction and incontinence, these stats mean that for every possible screened guy who avoids prostate cancer (because of the screening) up to 83 will have suffered a debilitating complication, and arguably one life-altering in the sense of taking away life quality. Thus, reading these another way, the average guy is 83 times more likely to suffer a complication somewhere along the line than he is to benefit from the screening. (Factor in the Task Force's finding that 80% of PSA tests yield false positives at some time, and you have major cause to be concerned that too many will be snookered into over-treatment based on some uro-guru's pronouncements).

Of course, on hearing the new guidelines (actually they were reinforced since being issued last year), the American Urological Association went ape shit. They blabbered 'Oh NO! You can't do that! This is the best test we have to prevent prostate cancer!" And as you watched them, you could just see the big dollar signs vanishing from their eyes, because make no mistake, if most men respond to these findings in a rational sense, the urologists will no longer be multi-millionaires. No longer will $1b a year be squandered on prostate biopsies (which now cost nearly as much as colonoscopies, and further - unlike colonoscopies- cannot even ensure at the 50% level you are cancer free!)

Now, is there a test which men might consider to further calm their frayed, hyper-reactive nerves, especially if they can't tolerate the thought of any kind of cancer growing (even slowly) inside them? There is, and it's called the free PSA. What it does is measure the ratio of the free prostate specific antigen in the blood to the total or bound PSA. Here's the deal: the lower the ratio the more likely there's prostate cancer.

In general, for patients with total PSA results between 4.0 and 10.0 ng/mL, free PSA measurements may be used to improve specificity, with biopsy restricted to patients whose percent free PSA is below some cutoff (20% in the case of one ACS guideline). If the free PSA is significantly above 25%, this generally signals a benign condition called "benign prostate hypertrophy" with 90% probability, and biopsy can be eschewed.

The point is, there is a more refined test if one seeks to pursue it, but it assumes the total PSA is already over 4.0 ng/mL.

In the end, the general guidelines are if you're healthy, don't have any genetic predispositions and experience no problems there's no need to get a PSA every year. Nor do you have to become hysterical or rush for a biopsy because some urologist says so, even if the PSA level jumps. But the best option may be to ditch the numbers fetishism, period - at least until the urological gurus come up with something less ambiguous.

Can a culture that's so mesmerized by changing numbers (such as the DOW) even remotely come to that state? Who knows, but it might be worth a try at least for some of us!

About Me

Specialized in space physics and solar physics, developed first astronomy curriculum for Caribbean secondary schools, has written thirteen books - the most recent:Fundamentals of Solar Physics. Also: Modern Physics: Notes, Problems and Solutions;:'Beyond Atheism, Beyond God', Astronomy & Astrophysics: Notes, Problems and Solutions', 'Physics Notes for Advanced Level&#39, Mathematical Excursions in Brane Space, Selected Analyses in Solar Flare Plasma Dynamics; and 'A History of Caribbean Secondary School Astronomy'. It details the background to my development and implementation of the first ever astronomy curriculum for secondary schools in the Caribbean.